Introduction to Well Logs and Log Analysis for New Hires

by

Robert Font, Ph.D., CPG, PG

A product of Geoscience Data Management, Inc.

© All Rights Reserved

180+ Power Point slides covering:

Introduction to petroleum geoscience

• Composition, properties and usage of hydrocarbons

• Global reserves, production and consumption

• Field size classification

• Basic geological and geophysical principles

• The four basic prerequisites for finding commercial hydrocarbons: source rock, reservoir rock, trap and seal, and perfect "timing"

• Exploration and the seismic method

• Integrating seismic with well control

• 2D, 3D, 4D seismic

• Leads and prospects

• Reserve calculations

• Exploration economics and risk analysis

• Well drilling

Well Logs

• Introduction to well logs, the main uses and types of well logs

• Lithologic and mud logs, "shows" and sidewall and conventional cores

• Wire-line logs - basic information
  
              The invasion profile, log header information, log tracks
  

• Electric logs
  
              Conventional (old) electric logs - how they work and what they measure
  
                          SP curve, normal resistivity curves, lateral resistivity curve, micrologs - finding petroleum using conventional electric logs
  
              Induction logs and laterologs - how they work and what they measure
  
              How to identify electric logs
  
                          Log header, scales, units, tracks, correlation versus detailed logs for analysis
  

• Basic porosity logs - how they work and what they measure
  
              Sonic or acoustic logs, density logs, neutron logs
  
              How to identify the basic porosity logs
  
                          Log header, scales, units, tracks
  

• Gamma ray logs, dipmeter logs and caliper logs - how they work and what they measure

• Important specialized logs - how they work and what they measure
  
              EPT logs, MRIL logs
  
              Air drilled logs
  
              Epithermal neutron logs, temperature logs, noise logs
  
              Dielectric constants logs
  
              MWD logs
  

• Cased hole or "completion" logs - how they work and what they measure
  
              CBL logs, CET logs, temperature and GR/neutron logs
  

• Production logs and through casing evaluation logs - how they work and what they measure
  
              Pulsed neutron tools, compensated neutron and gamma ray tools
  

• Log analysis - how it works and what it measures
  
              Water saturation and Archie's equation
  
              Quick-look methods
  
                          R_wa method, CDP method, Rxo/Rt method
  

• Deciding what logs to run
  
              For fresh water systems, for salt water systems, in oil-based muds
  

• Cataloging well logs
  
              What to look for and what to capture; establishing and complying with set standards; folder preparation and filing convention
  

• References and review questions